For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

For each assessment, 1.5 mL of blood was collected aseptically from the subject in the supine position by venipuncture or via an intravenous. catheter placed in an antecubital vein in the arm in ethylenediaminetetraacetic acid containing tubes. Immediately following collection of the required whole blood volume, the tubes were slowly tilted backwards and forwards (no shaking) to bring the anti-coagulant into solution. The anticoagulated whole blood stored at room temperature (20-25 °C) was preferably stained within 12 hours, at the latest 24 hours, and analyzed within 24 hours. The lymphocyte subset counts were analyzed by fluorescence activated cell sorting.

Blood samples for pharmacokinetic analysis were taken following drug administration on study Day 9 (Day 3 of the dosing period with 40 mg) and study Day 18 (Day 3 of the dosing period with 100 mg) and Cmax of ACT-128800 was determined by non-compartmental analysis.

Blood samples for pharmacokinetic analysis were taken following drug administration on study Day 9 (Day 3 of the dosing period with 40 mg) and study Day 18 (Day 3 of the dosing period with 100 mg) and AUC0-24 of ACT-128800 was determined by non-compartmental analysis.

Blood samples for pharmacokinetic analysis were taken following drug administration on study Day 18 (Day 3 of the dosing period with 100 mg) and AUC0-infinity of ACT-128800 was determined by non-compartmental analysis.

Blood samples for pharmacokinetic analysis were taken following drug administration on study Day 9 (Day 3 of the dosing period with 40 mg) and study Day 18 (Day 3 of the dosing period with 100 mg) and tmax of ACT-128800 was determined by non-compartmental analysis.

Blood samples for pharmacokinetic analysis were taken following drug administration on study Day 18 (Day 3 of the dosing period with 100 mg) and t1/2 of ACT-128800 was determined by non-compartmental analysis.